Its head of crime and anti-social behaviour, Michael Cartwright, said: “This is yet another example of police services in the borough being attacked by the government and the mayor of London. We’re very concerned about what these plans to close most of Fulham police station will mean for residents.”

The mayor says the creation of the 800-capacity school means he is delivering on his promise to alleviate pressure on London’s schools, while the police counter is proof of his commitment to the people of Fulham of his police and crime plan.

According to the Mayor’s office, only 35% of the policed station building is currently in use, making it an ideal site for the school. The Education Funding Agency has now agreed to purchase the under-used police building from the Mayor’s Office for Policing and Crime (MOPAC).

The free school is expected to move into its purpose-built new home on the site police station in September 2017.

Mr Johnson said: “I’m delighted that this under-used police station is going to provide an excellent and much-needed home for Fulham Boys School.

“The new free school will be a real community asset, giving 800 more pupils the opportunity to have a top-class education and I am pleased the site will also continue to provide a front-desk policing service for the local area.”

Chairman of Governors at FBS, Alex Wade, said: “We set out six years ago to provide an outstanding boys’ school for Fulham and I am delighted this news confirms our permanent presence in the heart of the borough.”

Alex Wade, chairman of governors at FBS

FBS patron and Chelsea & Fulham MP Greg Hands added: “I am overjoyed that we finally have a permanent site for the excellent Fulham Boys School. This comes after many years of searching and quite a number of twists and turns. I look forward to the school moving to its new site in the heart of Fulham in due course.”

The sale of the police station is part of MOPAC’s aim to provide a more efficient, cost-effective and modern police service, with proceeds being reinvested in front-line policing.

However, Cllr Cartwright said the council supported FBS but was “hugely disappointed that after a year of promises by the mayor to find a decent site Boris Johnson has not been able to come up with anything better than closing an important police station”, and questioned what service the front counter would offer.

He continued: “Fulham residents need a fully functional police station. The mayor must come clean about what the sale of the building means for a police presence in a fast growing area.”

But, H&F Neighbourhood Watch chairman David Millar was less concerned. He said: “The key thing form a Hammersmith & Fulham perspective is that they are going to up grade Hammersmith police station which in my view is not fit for purpose.

“At Fulham the police station is already subject to reduction in opening hours, and they’re planning to keep the front desk open so there will be public access which is a good thing.

“But beyond that, the way they operate, they don’t need to be based in a police station per se. There’s no reason why they can’t sell one property and reinvest making another fit for purpose.”